[Typing of pseudomonas aeruginosa by pyocine production. Experiments with a simplified method using four indicator
Abstract:
A further differentiation of strains of Pseudomonas aeruginosa which have been isolated from clinical material is desirable because of the increasing frequency of hospital infections caused by this species. Only by such a procedure cross infections which require hygienic measures can be distinguished from autoinfections. Pyocine typing with a set of only four indicator strains was tried by repeated typing of 542 strains. Because of its simplicity and the small amount of material and working time required the method was found to be suitable for routine application. Reproducibility was satisfactory. The strains tested could be grouped into nine different pyocine types. Similar to the results of other typing procedures, 74 per cent of the strains belonged to three groups. The method is suitable for detection of sources of hospital infections caused by the more rare pyocine types. By a comparison of the antibiotic resistance patterns with pyocine types in strains which had been isolated from patients with chronic infections it was demonstrated that antibiotic resistance patterns could not be used as criteria for epidemiological investigations.
Insights
Differentiating Pseudomonas aeruginosa strains using pyocine typing is crucial for tracking hospital infections. This simple, reproducible method effectively categorizes strains, aiding in identifying infection sources.
Area of Science:
- Clinical Microbiology
- Infectious Diseases
- Bacteriology
Background:
- Pseudomonas aeruginosa is a frequent cause of hospital-acquired infections.
- Differentiating strains is essential for distinguishing between cross-infections and autoinfections.
Purpose of the Study:
- To evaluate the efficacy of pyocine typing for differentiating clinical isolates of Pseudomonas aeruginosa.
- To determine if pyocine typing is suitable for routine laboratory application and epidemiological investigations.
Main Methods:
- Pyocine typing was performed on 542 Pseudomonas aeruginosa strains using a set of four indicator strains.
- The reproducibility and simplicity of the method were assessed.
- Antibiotic resistance patterns were compared with pyocine types in chronic infection isolates.
Main Results:
- The pyocine typing method successfully grouped the 542 strains into nine distinct types.
- 74% of strains belonged to three main pyocine types, consistent with other typing methods.
- The method proved simple, required minimal resources, and demonstrated satisfactory reproducibility.
- Pyocine typing effectively identified sources of hospital infections, especially for rarer types.
Conclusions:
- Pyocine typing is a practical and reliable method for routine differentiation of Pseudomonas aeruginosa clinical isolates.
- This technique aids in the epidemiological surveillance of hospital-acquired infections caused by this pathogen.
- Antibiotic resistance patterns are not suitable for epidemiological investigations of Pseudomonas aeruginosa in chronic infections.
